Volume 16, Issue 3, 2016 July-September

Volume 16, No 3 Pages:
2016 July-September Articles: 6

Tobacco-specific nitrosamines in tuibur

Nicotine, not a carcinogen per se, is one of the most addictive substances known. Tobacco smoke contains a vast number of chemicals with important biological effects in disease processes. Tobacco use is a global epidemic and the adverse health conditions including cardio-vascular diseases, atherosclerosis, and cancer are the manifestations of sustained tobacco consumption. Cancer is a major public health burden in both developed and developing countries. Tuibur, considered as ‘smokeless’ tobacco product in Mizoram, is presumed as one of the “safe” nicotine delivery media. In this mini-review, few tobacco-specific carcinogens detected in tuibur solution and their potential effects on biological systems are discussed.

Litter decomposition and nutrient release pattern in two nitrogen fixing shrubs (Flemingia macrophylla and Tephrosia candida) growing in SALT farm in Lunglei district of Mizoram

We studied litter decomposition and nutrient release patterns in different components of two nitrogen (N) fixing shrub species, (Flemingia macrophylla and Tephrosia candida) planted on sloping agriculture land technology (SALT) farm in 2002 and 2010. The two sites were 10 yrs old and 2 yrs old farms at the beginning of this study, i.e. July 2012. Sites were within the same permanent agriculture farm having similar climatic conditions. We collected different litter components (leaves green and senesced, wood and roots fine and coarse) of two species having different ages. Known amount (7 g) of all litter components were enclosed in nylon net mesh bags and placed in their respective habitats for decomposition and these samples were retrieved periodically to assess the rate of change of mass and nutrient. Our results suggest that the mean relative decomposition rates of different litter were maximum in the rainy season and minimum in the summer season for both sites and species. Among the litter components, fine roots (<2 mm) of both species showed higher rates of organic matter decomposition and rates of nutrient release to the soil. The rate of release of organic matter and nutrient was slightly greater in F. macrophylla than the T. candida. Annually, these species added significant amount of organic matter and nutrients to the soil that supported considerably higher production compared to shifting cultivation sites on sustained basis.

Etiology of lung cancer among the Mizo people

According to the National Cancer Registry Programme, Mizoram has the highest cancer incidence among the states of India. Lung cancer has been found to be very common among the Mizos and its etiology has never been scientifically analyzed in this high cancer incidence population. A hospital based case-control study was conducted during March, 2014 to February, 2016. The study involved 106 histologically confirmed lung cancer patients and 212 matched cancer-free subjects acting as controls, all with the same ethnic background, i.e. Mizo. Among the cases, the risk of lung cancer was significantly elevated among ex-smokers (OR, 4.69; 95% CI, 2.36-9.32), but not among current smokers. Higher risks were seen for zozial smokers (OR, 2.51; 95% CI, 1.28-4.92). The increased risk was apparent among subjects who had smoked for ≥40 years. Exposure to environmental smoke at home and workplace were significantly associated with an increased risk of lung cancer. Higher risk was also observed for previous diagnosis of asthma (OR, 4.62; 95% CI, 1.75-12.23). Lower consumption of alcohol related with decreased risk of lung cancer (OR, 0.87; 95% CI, 0.37-2.05). Tobacco smoking was found to be the primary factor for developing lung cancer. Certain occupations like the transport industry, farming, carpentry or automobile works were found to increase the risk of lung cancer. Prior affliction with tuberculosis might also have the potential to increase the risk. However, low and moderate consumption of alcohol leads to decrease risk of lung cancer.

Organocatalysts: A powerful tool for asymmetric Michael addition

In recent years, asymmetric organocatalysis has emerged as powerful tools for the synthesis of a variety of chiral molecules. Ready availability of the catalysts, low toxicity, simple operational procedures and mild reaction conditions associated with organocatalysis makes it an attractive method to synthesise diverse complex structures. Here, a short review on the development and applications of chiral organocatalysts for asymmetric Michael addition reactions has been described.

Impact of shifting cultivation on soil organic carbon in tropical hilly terrain of Mizoram, India

Shifting cultivation is one of the main forms of crop husbandry in the hilly northeast India and is known to change the physico-chemical properties of soil. Data of soil organic carbon (SOC) in relation to shifting cultivation is not available in Mizoram. The study was conducted in an experimental plot of 1-acre area in the natural forest at Khawrihnim village located about 50 km south-west of Aizawl, Mizoram. Five random soil samples each were collected from shifting cultivation (experimental EXPTL) and natural forest (control CTRL) sites at monthly intervals between 2013 and 2015 at three different soil strata (i.e. 0-10 cm, 10-20 cm and 20-30 cm). SOC was estimated in percent by rapid dichromate oxidation method. Shifting cultivation has positive significant effect on SOC content. Compare to pre- and post-Jhum cultivation, the Two-Way ANOVA indicates significant increased of SOC (p<0.05) in the jhum cultivation year, which may be due to burning effect and the weeding practice that coincides with the onset of monsoon rains. The onset of monsoon after the burning of slashed vegetation and the first weeding accelerate the decomposition rate and soil microbial activity. The average of SOC in the surface layer increased from first year to third year by 1.34%. However, significant decreased of SOC content with increased in soil depth (p<0.001) was also recorded in both EXPTL and CTRL sites.

Prevalence of helminth parasites infecting Mastacembelus armatus (Lacepède, 1800) from different rivers of Mizoram, northeast India

The study deals with the prevalence of helminth parasites in Mastacembelus armatus, a spiny eel, collected from the rivers of Mizoram. The study gives the first overview on the helminth community infecting M. armatus in the rivers of Mizoram and reveals the presence of nematode, cestode and trematode. The cestodes recovered belongs to the genus Senga sp. and Bothriocephalus sp. whereas the nematode belong to the genus Spinitectus sp., Neocamallanus sp., Capillaria sp. and Eustrongylides sp. and the trematode Clinostomum sp. Nematode was found to be the most predominant parasitic group followed by cestode and the trematode respectively. The Tuikum and Tuirial rivers flowing near the garbage dumping ground show the maximum diversity with all the three group of parasites present. Among the helminth parasite recovered the nematode Capillaria sp. and the trematode Clinostomum sp. are both considered potential zoonoses.